Composite Tube Assembly Reusable End Fittings
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Solution Overview
Problem
Conventional composite tube assemblies with metallic end fittings bonded to composite tubes hinder the reuse of these fittings when replacing the tubes, as the bonding process makes it difficult to separate and reutilize the end fittings.
Innovation Solution
A composite tube assembly design featuring a compression sleeve with a constant outer diameter coupled to the composite tube, a carbon extrusion member, and an end fitting with a tapered locking feature that engages the carbon extrusion member, allowing for radially outward expansion under tensile load, enabling the reuse of metallic end fittings.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Strength
If metallic end fittings are bonded to composite tubes, then structural strength and rigidity are improved, but reuse of end fittings is hindered
Solution Approach 1:
The assembly is divided into separable components: the composite tube, the metallic end fitting, and a retention mechanism (such as a bayonet-style connector or interference-fit interface). This allows the end fitting to be detached and reused on different tubes, eliminating the waste associated with bonded connections while maintaining structural integrity during use.
Solution Approach 2:
The design enables recovery and reuse of the metallic end fitting after the composite tube reaches its service life. The retention mechanism allows for controlled detachment, ensuring that the expensive metallic component can be recovered and reused multiple times, reducing material waste and manufacturing costs.
2Ease of manufacture
If conventional bonding methods are used to attach end fittings, then manufacturing simplicity is maintained, but environmental sustainability deteriorates
Solution Approach 1:
The connection system is segmented into reusable metallic end fittings and replaceable composite tubes. This segmentation enables the metallic components to be recovered and reused, significantly reducing material waste while maintaining relatively simple manufacturing processes for both the tubes and fittings.
Solution Approach 2:
The design implements a recover-and-reuse system where metallic end fittings are discarded from worn tubes and recovered for reuse on new tubes. This approach dramatically reduces material waste, particularly of expensive metallic materials, while the manufacturing process remains straightforward through standardized connection interfaces.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Facilitates the reuse of metallic end fittings by allowing them to be easily removed and reinstalled, maintaining structural integrity and leveraging the anisotropic properties of the composite materials for enhanced load transfer and durability.
Implementation Method 1
the locking feature is configured to radially expand the carbon extrusion member
Implementation Method 2
the compression sleeve exerts a radially inward compression force against the carbon extrusion member and the locking feature
Data Source
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AI summary
Composite tubes (130) comprising a compression sleeve (120) coupled to an inner surface (190) of a composite tube, a carbon extrusion member (140) disposed within the composite tube, and an end fitting (110) comprising a locking feature (150), wherein the end fitting is coupled to an inner surface (170) of the compression sleeve and the locking feature is configured to engage the carbon extrusion member are disclosed. Methods comprising coupling a compression sleeveto an inner surface of a distal end of a composite tube, placing a carbon extrusion member inside the compression sleeve and the composite tube, and disposing an end fitting on the distal end of the composite tube, wherein the end fitting comprises a locking feature configured to interact with the carbon extrusion member are also disclosed.